<!doctype html>
<html lang="en">	
	<head>
		<meta charset="UTF-8">
		<meta name="Generator" content="EditPlus®">
		<meta name="Author" content="">
		<meta name="Keywords" content="">
		<meta name="Description" content="">
		<title>Document</title>
		<style>
			*{margin:0;padding:0;}
			a{text-decoration:none;}
			ul,li{list-style:none;}
			body{font-size:12px;font-family:"微软雅黑";}
			section{
				width:300px;
				height:100px;
				background:red;
				margin:10px auto;
			}
			section div{
				position:relative;
				float:left;
				width:100px;
				height:100px;
				background:green;
			}	
			section div:after{
				position:absolute;
				top:0;
				right:1px;
				display:block;
				width:1px;
				height:100px;
				background:yellow;
				content:"";
			}
			/*暂用class选择器 和id选择器*/
			section #box:after{width:0px;}
		</style>
	</head>
	<body>
		
		<section>
			<div></div>
			<div></div>
			<div id="box"></div>
		</section>
		
		
	</body>
</html>
